1
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Lee WJ, Kim SJ, Ahn Y, Park J, Jin S, Jang J, Jeong J, Park M, Lee YS, Lee J, Seo D. From Homogeneity to Turing Pattern: Kinetically Controlled Self-Organization of Transmembrane Protein. NANO LETTERS 2024; 24:1882-1890. [PMID: 38198287 DOI: 10.1021/acs.nanolett.3c03637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Understanding the spatial organization of membrane proteins is crucial for unraveling key principles in cell biology. The reaction-diffusion model is commonly used to understand biochemical patterning; however, applying reaction-diffusion models to subcellular phenomena is challenging because of the difficulty in measuring protein diffusivity and interaction kinetics in the living cell. In this work, we investigated the self-organization of the plasmalemma vesicle-associated protein (PLVAP), which creates regular arrangements of fenestrated ultrastructures, using single-molecule tracking. We demonstrated that the spatial organization of the ultrastructures is associated with a decrease in the association rate by actin destabilization. We also constructed a reaction-diffusion model that accurately generates a hexagonal array with the same 130 nm spacing as the actual scale and informs the stoichiometry of the ultrastructure, which can be discerned only through electron microscopy. Through this study, we integrated single-molecule experiments and reaction-diffusion modeling to surpass the limitations of static imaging tools and proposed emergent properties of the PLVAP ultrastructure.
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Affiliation(s)
- Wonhee John Lee
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
| | - Soo Jin Kim
- Department of Medical Science, AMIST, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Yongdeok Ahn
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
| | - Jiseong Park
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
| | - Siwoo Jin
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
| | - Juhee Jang
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
| | - Jinju Jeong
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - Minsoo Park
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
| | - Young-Sam Lee
- Department of New Biology, DGIST, Daegu 42988, Republic of Korea
| | - Junyeop Lee
- Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
- Translational Biomedical Research Group, Asan Institute for Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea
| | - Daeha Seo
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
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2
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Abstract
Developing organs are shaped, in part, by physical interaction with their environment in the embryo. In recent years, technical advances in live-cell imaging and material science have greatly expanded our understanding of the mechanical forces driving organ formation. Here, we provide a broad overview of the types of forces generated during embryonic development and then focus on a subset of organs underlying our senses: the eyes, inner ears, nose and skin. The epithelia in these organs emerge from a common origin: the ectoderm germ layer; yet, they arrive at unique and complex forms over developmental time. We discuss exciting recent animal studies that show a crucial role for mechanical forces in, for example, the thickening of sensory placodes, the coiling of the cochlea and the lengthening of hair. Finally, we discuss how microfabricated organoid systems can now provide unprecedented insights into the physical principles of human development.
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Affiliation(s)
- Anh Phuong Le
- Department of Otolaryngology, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Plastic and Oral Surgery, Boston Children's Hospital, Boston, MA 02115, USA
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Jin Kim
- Department of Otolaryngology, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Plastic and Oral Surgery, Boston Children's Hospital, Boston, MA 02115, USA
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Karl R. Koehler
- Department of Otolaryngology, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Plastic and Oral Surgery, Boston Children's Hospital, Boston, MA 02115, USA
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA
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3
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Miller KK, Atkinson P, Mendoza KR, Ó Maoiléidigh D, Grillet N. Dimensions of a Living Cochlear Hair Bundle. Front Cell Dev Biol 2021; 9:742529. [PMID: 34900993 PMCID: PMC8657763 DOI: 10.3389/fcell.2021.742529] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/13/2021] [Indexed: 11/23/2022] Open
Abstract
The hair bundle is the mechanosensory organelle of hair cells that detects mechanical stimuli caused by sounds, head motions, and fluid flows. Each hair bundle is an assembly of cellular-protrusions called stereocilia, which differ in height to form a staircase. Stereocilia have different heights, widths, and separations in different species, sensory organs, positions within an organ, hair-cell types, and even within a single hair bundle. The dimensions of the stereociliary assembly dictate how the hair bundle responds to stimuli. These hair-bundle properties have been measured previously only to a limited degree. In particular, mammalian data are either incomplete, lack control for age or position within an organ, or have artifacts owing to fixation or dehydration. Here, we provide a complete set of measurements for postnatal day (P) 11 C57BL/6J mouse apical inner hair cells (IHCs) obtained from living tissue, tissue mildly-fixed for fluorescent imaging, or tissue strongly fixed and dehydrated for scanning electronic microscopy (SEM). We found that hair bundles mildly-fixed for fluorescence had the same dimensions as living hair bundles, whereas SEM-prepared hair bundles shrank uniformly in stereociliary heights, widths, and separations. By determining the shrinkage factors, we imputed live dimensions from SEM that were too small to observe optically. Accordingly, we created the first complete blueprint of a living IHC hair bundle. We show that SEM-prepared measurements strongly affect calculations of a bundle’s mechanical properties – overestimating stereociliary deflection stiffness and underestimating the fluid coupling between stereocilia. The methods of measurement, the data, and the consequences we describe illustrate the high levels of accuracy and precision required to understand hair-bundle mechanotransduction.
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Affiliation(s)
- Katharine K Miller
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, CA, United States
| | - Patrick Atkinson
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, CA, United States
| | - Kyssia Ruth Mendoza
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, CA, United States
| | - Dáibhid Ó Maoiléidigh
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, CA, United States
| | - Nicolas Grillet
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, CA, United States
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4
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Wang D, Zhou J. The Kinocilia of Cochlear Hair Cells: Structures, Functions, and Diseases. Front Cell Dev Biol 2021; 9:715037. [PMID: 34422834 PMCID: PMC8374625 DOI: 10.3389/fcell.2021.715037] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/14/2021] [Indexed: 12/11/2022] Open
Abstract
Primary cilia are evolutionarily conserved and highly specialized organelles that protrude from cell membranes. Mutations in genes encoding ciliary proteins can cause structural and functional ciliary defects and consequently multiple diseases, collectively termed ciliopathies. The mammalian auditory system is responsible for perceiving external sound stimuli that are ultimately processed in the brain through a series of physical and biochemical reactions. Here we review the structure and function of the specialized primary cilia of hair cells, termed kinocilia, found in the mammalian auditory system. We also discuss areas that might prove amenable for therapeutic management of auditory ciliopathies.
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Affiliation(s)
- Difei Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Jun Zhou
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
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5
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Mancinelli G, Galic M. Exploring the interdependence between self-organization and functional morphology in cellular systems. J Cell Sci 2020; 133:133/13/jcs242479. [PMID: 32620564 DOI: 10.1242/jcs.242479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
All living matter is subject to continuous adaptation and functional optimization via natural selection. Consequentially, structures with close morphological resemblance repeatedly appear across the phylogenetic tree. How these designs emerge at the cellular level is not fully understood. Here, we explore core concepts of functional morphology and discuss its cause and consequences, with a specific focus on emerging properties of self-organizing systems as the potential driving force. We conclude with open questions and limitations that are present when studying shape-function interdependence in single cells and cellular ensembles.
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Affiliation(s)
- Gloria Mancinelli
- 'Cells in Motion' Interfaculty Centre, University of Muenster, 48149 Muenster, Germany.,Institute of Medical Physics and Biophysics, Medical Faculty, University of Muenster, 49149 Muenster, Germany.,CIM-IMRPS Graduate Program, 48149 Muenster, Germany
| | - Milos Galic
- 'Cells in Motion' Interfaculty Centre, University of Muenster, 48149 Muenster, Germany .,Institute of Medical Physics and Biophysics, Medical Faculty, University of Muenster, 49149 Muenster, Germany
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6
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Silva-Dias L, Lopez-Castillo A. Turing patterns modulation by chemical gradient in isothermal and non-isothermal conditions. Phys Chem Chem Phys 2020; 22:7507-7515. [DOI: 10.1039/d0cp00650e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chemical gradients imposed through boundary conditions induce spatial symmetry breaking of Turing patterns in small systems.
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7
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Saha T, Galic M. Self-organization across scales: from molecules to organisms. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0113. [PMID: 29632265 DOI: 10.1098/rstb.2017.0113] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2017] [Indexed: 11/12/2022] Open
Abstract
Creating ordered structures from chaotic environments is at the core of biological processes at the subcellular, cellular and organismic level. In this perspective, we explore the physical as well as biological features of two prominent concepts driving self-organization, namely phase transition and reaction-diffusion, before closing with a discussion on open questions and future challenges associated with studying self-organizing systems.This article is part of the theme issue 'Self-organization in cell biology'.
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Affiliation(s)
- Tanumoy Saha
- DFG Cluster of Excellence 'Cells in Motion', (EXC 1003), University of Muenster, Waldeyerstrasse 15, 48149 Muenster, Germany.,Institute of Medical Physics and Biophysics, University of Muenster, Robert-Koch-Strasse 31, 48149 Muenster, Germany
| | - Milos Galic
- DFG Cluster of Excellence 'Cells in Motion', (EXC 1003), University of Muenster, Waldeyerstrasse 15, 48149 Muenster, Germany .,Institute of Medical Physics and Biophysics, University of Muenster, Robert-Koch-Strasse 31, 48149 Muenster, Germany
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8
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Norman J, Sorrell EL, Hu Y, Siripurapu V, Garcia J, Bagwell J, Charbonneau P, Lubkin SR, Bagnat M. Tissue self-organization underlies morphogenesis of the notochord. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2017.0320. [PMID: 30249771 DOI: 10.1098/rstb.2017.0320] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2018] [Indexed: 12/13/2022] Open
Abstract
The notochord is a conserved axial structure that in vertebrates serves as a hydrostatic scaffold for embryonic axis elongation and, later on, for proper spine assembly. It consists of a core of large fluid-filled vacuolated cells surrounded by an epithelial sheath that is encased in extracellular matrix. During morphogenesis, the vacuolated cells inflate their vacuole and arrange in a stereotypical staircase pattern. We investigated the origin of this pattern and found that it can be achieved purely by simple physical principles. We are able to model the arrangement of vacuolated cells within the zebrafish notochord using a physical model composed of silicone tubes and water-absorbing polymer beads. The biological structure and the physical model can be accurately described by the theory developed for the packing of spheres and foams in cylinders. Our experiments with physical models and numerical simulations generated several predictions on key features of notochord organization that we documented and tested experimentally in zebrafish. Altogether, our data reveal that the organization of the vertebrate notochord is governed by the density of the osmotically swelling vacuolated cells and the aspect ratio of the notochord rod. We therefore conclude that self-organization underlies morphogenesis of the vertebrate notochord.This article is part of the Theo Murphy meeting issue on 'Mechanics of development'.
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Affiliation(s)
- James Norman
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Emma L Sorrell
- Department of Cell Biology, Duke University, Durham, NC 27710, USA.,Department of Mathematics, North Carolina State University, Raleigh, NC 27695-8205, USA
| | - Yi Hu
- Department of Chemistry, Duke University, Durham, NC 27710, USA
| | - Vaishnavi Siripurapu
- Department of Cell Biology, Duke University, Durham, NC 27710, USA.,North Carolina School of Science and Mathematics, Durham, NC 27705, USA
| | - Jamie Garcia
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | - Jennifer Bagwell
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
| | | | - Sharon R Lubkin
- Department of Mathematics, North Carolina State University, Raleigh, NC 27695-8205, USA
| | - Michel Bagnat
- Department of Cell Biology, Duke University, Durham, NC 27710, USA
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9
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Abstract
It is well known that temporal first-derivative reaction-diffusion systems can produce various fascinating Turing patterns. However, it has been found that many physical, chemical and biological systems are well described by temporal fractional-derivative reaction-diffusion equations. Naturally arises an issue whether and how spatial patterns form for such a kind of systems. To address this issue clearly, we consider a classical prey-predator diffusive model with the Holling II functional response, where temporal fractional derivatives are introduced according to the memory character of prey’s and predator’s behaviors. In this paper, we show that this fractional-derivative system can form steadily spatial patterns even though its first-derivative counterpart can’t exhibit any steady pattern. This result implies that the temporal fractional derivatives can induce spatial patterns, which enriches the current mechanisms of pattern formation.
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10
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Zhang L, Köhler S, Rillo-Bohn R, Dernburg AF. A compartmentalized signaling network mediates crossover control in meiosis. eLife 2018. [PMID: 29521627 DOI: 10.7554/elife.30789.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023] Open
Abstract
During meiosis, each pair of homologous chromosomes typically undergoes at least one crossover (crossover assurance), but these exchanges are strictly limited in number and widely spaced along chromosomes (crossover interference). The molecular basis for this chromosome-wide regulation remains mysterious. A family of meiotic RING finger proteins has been implicated in crossover regulation across eukaryotes. Caenorhabditis elegans expresses four such proteins, of which one (ZHP-3) is known to be required for crossovers. Here we investigate the functions of ZHP-1, ZHP-2, and ZHP-4. We find that all four ZHP proteins, like their homologs in other species, localize to the synaptonemal complex, an unusual, liquid crystalline compartment that assembles between paired homologs. Together they promote accumulation of pro-crossover factors, including ZHP-3 and ZHP-4, at a single recombination intermediate, thereby patterning exchanges along paired chromosomes. These proteins also act at the top of a hierarchical, symmetry-breaking process that enables crossovers to direct accurate chromosome segregation.
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Affiliation(s)
- Liangyu Zhang
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
- Howard Hughes Medical Institute, Chevy Chase, United States
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, United States
- California Institute for Quantitative Biosciences, Berkeley, United States
| | - Simone Köhler
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
- Howard Hughes Medical Institute, Chevy Chase, United States
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, United States
- California Institute for Quantitative Biosciences, Berkeley, United States
| | - Regina Rillo-Bohn
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
- Howard Hughes Medical Institute, Chevy Chase, United States
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, United States
- California Institute for Quantitative Biosciences, Berkeley, United States
| | - Abby F Dernburg
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
- Howard Hughes Medical Institute, Chevy Chase, United States
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, United States
- California Institute for Quantitative Biosciences, Berkeley, United States
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11
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Zhang L, Köhler S, Rillo-Bohn R, Dernburg AF. A compartmentalized signaling network mediates crossover control in meiosis. eLife 2018; 7:e30789. [PMID: 29521627 PMCID: PMC5906097 DOI: 10.7554/elife.30789] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 03/08/2018] [Indexed: 01/01/2023] Open
Abstract
During meiosis, each pair of homologous chromosomes typically undergoes at least one crossover (crossover assurance), but these exchanges are strictly limited in number and widely spaced along chromosomes (crossover interference). The molecular basis for this chromosome-wide regulation remains mysterious. A family of meiotic RING finger proteins has been implicated in crossover regulation across eukaryotes. Caenorhabditis elegans expresses four such proteins, of which one (ZHP-3) is known to be required for crossovers. Here we investigate the functions of ZHP-1, ZHP-2, and ZHP-4. We find that all four ZHP proteins, like their homologs in other species, localize to the synaptonemal complex, an unusual, liquid crystalline compartment that assembles between paired homologs. Together they promote accumulation of pro-crossover factors, including ZHP-3 and ZHP-4, at a single recombination intermediate, thereby patterning exchanges along paired chromosomes. These proteins also act at the top of a hierarchical, symmetry-breaking process that enables crossovers to direct accurate chromosome segregation.
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Affiliation(s)
- Liangyu Zhang
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering DivisionLawrence Berkeley National LaboratoryBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
| | - Simone Köhler
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering DivisionLawrence Berkeley National LaboratoryBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
| | - Regina Rillo-Bohn
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering DivisionLawrence Berkeley National LaboratoryBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
| | - Abby F Dernburg
- Department of Molecular and Cell BiologyUniversity of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering DivisionLawrence Berkeley National LaboratoryBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
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12
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Abstract
The hair bundle—the sensory organelle of inner-ear hair cells of vertebrates—exemplifies the ability of a cell to assemble complex, elegant structures. Proper construction of the bundle is required for proper mechanotransduction in response to external forces and to transmit information about sound and movement. Bundles contain tightly controlled numbers of actin-filled stereocilia, which are arranged in defined rows of precise heights. Indeed, many deafness mutations that disable hair-cell cytoskeletal proteins also disrupt bundles. Bundle assembly is a tractable problem in molecular and cellular systems biology; the sequence of structural changes in stereocilia is known, and a modest number of proteins may be involved.
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Affiliation(s)
- Peter-G Barr-Gillespie
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, OR 97239
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13
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Ebrahim S, Avenarius MR, Grati M, Krey JF, Windsor AM, Sousa AD, Ballesteros A, Cui R, Millis BA, Salles FT, Baird MA, Davidson MW, Jones SM, Choi D, Dong L, Raval MH, Yengo CM, Barr-Gillespie PG, Kachar B. Stereocilia-staircase spacing is influenced by myosin III motors and their cargos espin-1 and espin-like. Nat Commun 2016; 7:10833. [PMID: 26926603 PMCID: PMC4773517 DOI: 10.1038/ncomms10833] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 01/25/2016] [Indexed: 12/12/2022] Open
Abstract
Hair cells tightly control the dimensions of their stereocilia, which are actin-rich protrusions with graded heights that mediate mechanotransduction in the inner ear. Two members of the myosin-III family, MYO3A and MYO3B, are thought to regulate stereocilia length by transporting cargos that control actin polymerization at stereocilia tips. We show that eliminating espin-1 (ESPN-1), an isoform of ESPN and a myosin-III cargo, dramatically alters the slope of the stereocilia staircase in a subset of hair cells. Furthermore, we show that espin-like (ESPNL), primarily present in developing stereocilia, is also a myosin-III cargo and is essential for normal hearing. ESPN-1 and ESPNL each bind MYO3A and MYO3B, but differentially influence how the two motors function. Consequently, functional properties of different motor-cargo combinations differentially affect molecular transport and the length of actin protrusions. This mechanism is used by hair cells to establish the required range of stereocilia lengths within a single cell.
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Affiliation(s)
- Seham Ebrahim
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Matthew R Avenarius
- Oregon Hearing Research Center and Vollum Institute, Oregon Health &Science University, Portland, Oregon 97239, USA
| | - M'hamed Grati
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jocelyn F Krey
- Oregon Hearing Research Center and Vollum Institute, Oregon Health &Science University, Portland, Oregon 97239, USA
| | - Alanna M Windsor
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Aurea D Sousa
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Angela Ballesteros
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Runjia Cui
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Bryan A Millis
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Felipe T Salles
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Michelle A Baird
- National High Magnetic Field Laboratory and Department of Biological Science, Florida State University, Tallahassee, Florida 32310, USA
| | - Michael W Davidson
- National High Magnetic Field Laboratory and Department of Biological Science, Florida State University, Tallahassee, Florida 32310, USA
| | - Sherri M Jones
- Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA
| | - Dongseok Choi
- Department of Public Health and Preventive Medicine, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Manmeet H Raval
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | - Christopher M Yengo
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA
| | - Peter G Barr-Gillespie
- Oregon Hearing Research Center and Vollum Institute, Oregon Health &Science University, Portland, Oregon 97239, USA
| | - Bechara Kachar
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, USA
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14
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Bhonker Y, Abu-Rayyan A, Ushakov K, Amir-Zilberstein L, Shivatzki S, Yizhar-Barnea O, Elkan-Miller T, Tayeb-Fligelman E, Kim SM, Landau M, Kanaan M, Chen P, Matsuzaki F, Sprinzak D, Avraham KB. The GPSM2/LGN GoLoco motifs are essential for hearing. Mamm Genome 2015; 27:29-46. [PMID: 26662512 DOI: 10.1007/s00335-015-9614-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 11/17/2015] [Indexed: 11/24/2022]
Abstract
The planar cell polarity (PCP) pathway is responsible for polarizing and orienting cochlear hair cells during development through movement of a primary cilium, the kinocilium. GPSM2/LGN, a mitotic spindle-orienting protein associated with deafness in humans, is a PCP effector involved in kinocilium migration. Here, we link human and mouse truncating mutations in the GPSM2/LGN gene, both leading to hearing loss. The human variant, p.(Trp326*), was identified by targeted genomic enrichment of genes associated with deafness, followed by massively parallel sequencing. Lgn (ΔC) mice, with a targeted deletion truncating the C-terminal GoLoco motifs, are profoundly deaf and show misorientation of the hair bundle and severe malformations in stereocilia shape that deteriorates over time. Full-length protein levels are greatly reduced in mutant mice, with upregulated mRNA levels. The truncated Lgn (ΔC) allele is translated in vitro, suggesting that mutant mice may have partially functioning Lgn. Gαi and aPKC, known to function in the same pathway as Lgn, are dependent on Lgn for proper localization. The polarization of core PCP proteins is not affected in Lgn mutants; however, Lgn and Gαi are misoriented in a PCP mutant, supporting the role of Lgn as a PCP effector. The kinocilium, previously shown to be dependent on Lgn for robust localization, is essential for proper localization of Lgn, as well as Gαi and aPKC, suggesting that cilium function plays a role in positioning of apical proteins. Taken together, our data provide a mechanism for the loss of hearing found in human patients with GPSM2/LGN variants.
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Affiliation(s)
- Yoni Bhonker
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Amal Abu-Rayyan
- Department of Biological Sciences, Bethlehem University, Bethlehem, Palestine
| | - Kathy Ushakov
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Liat Amir-Zilberstein
- Department of Biochemistry and Molecular Biology, Weiss Faculty of Life Sciences, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Shaked Shivatzki
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Ofer Yizhar-Barnea
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Tal Elkan-Miller
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Einav Tayeb-Fligelman
- Department of Biology, Technion-Israel Institute of Technology, 32000, Haifa, Israel
| | - Sun Myoung Kim
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
| | - Meytal Landau
- Department of Biology, Technion-Israel Institute of Technology, 32000, Haifa, Israel
| | - Moien Kanaan
- Department of Biological Sciences, Bethlehem University, Bethlehem, Palestine
| | - Ping Chen
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
| | - Fumio Matsuzaki
- Laboratory of Cell Asymmetry, Center for Developmental Biology, Riken, Kobe, 650-0047, Japan
| | - David Sprinzak
- Department of Biochemistry and Molecular Biology, Weiss Faculty of Life Sciences, Tel Aviv University, 69978, Tel Aviv, Israel
| | - Karen B Avraham
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel.
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15
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Lu X, Sipe CW. Developmental regulation of planar cell polarity and hair-bundle morphogenesis in auditory hair cells: lessons from human and mouse genetics. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 5:85-101. [PMID: 26265594 DOI: 10.1002/wdev.202] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/12/2015] [Accepted: 06/29/2015] [Indexed: 12/11/2022]
Abstract
Hearing loss is the most common and costly sensory defect in humans and genetic causes underlie a significant proportion of affected individuals. In mammals, sound is detected by hair cells (HCs) housed in the cochlea of the inner ear, whose function depends on a highly specialized mechanotransduction organelle, the hair bundle. Understanding the factors that regulate the development and functional maturation of the hair bundle is crucial for understanding the pathophysiology of human deafness. Genetic analysis of deafness genes in animal models, together with complementary forward genetic screens and conditional knock-out mutations in essential genes, have provided great insights into the molecular machinery underpinning hair-bundle development and function. In this review, we highlight recent advances in our understanding of hair-bundle morphogenesis, with an emphasis on the molecular pathways governing hair-bundle polarity and orientation. We next discuss the proteins and structural elements important for hair-cell mechanotransduction as well as hair-bundle cohesion and maintenance. In addition, developmental signals thought to regulate tonotopic features of HCs are introduced. Finally, novel approaches that complement classic genetics for studying the molecular etiology of human deafness are presented. WIREs Dev Biol 2016, 5:85-101. doi: 10.1002/wdev.202 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Xiaowei Lu
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Conor W Sipe
- Department of Biology, University of Virginia, Charlottesville, VA, USA
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16
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Jahan I, Pan N, Kersigo J, Fritzsch B. Neurog1 can partially substitute for Atoh1 function in hair cell differentiation and maintenance during organ of Corti development. Development 2015. [PMID: 26209643 DOI: 10.1242/dev.123091] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Atoh1, a basic helix-loop-helix (bHLH) transcription factor (TF), is essential for the differentiation of hair cells (HCs), mechanotransducers that convert sound into auditory signals in the mammalian organ of Corti (OC). Previous work demonstrated that replacing mouse Atoh1 with the fly ortholog atonal rescues HC differentiation, indicating functional replacement by other bHLH genes. However, replacing Atoh1 with Neurog1 resulted in reduced HC differentiation compared with transient Atoh1 expression in a 'self-terminating' Atoh1 conditional null mouse (Atoh1-Cre; Atoh1(f/f)). We now show that combining Neurog1 in one allele with removal of floxed Atoh1 in a self-terminating conditional mutant (Atoh1-Cre; Atoh1(f/kiNeurog1)) mouse results in significantly more differentiated inner HCs and outer HCs that have a prolonged longevity of 9 months compared with Atoh1 self-terminating littermates. Stereocilia bundles are partially disorganized, disoriented and not HC type specific. Replacement of Atoh1 with Neurog1 maintains limited expression of Pou4f3 and Barhl1 and rescues HCs quantitatively, but not qualitatively. OC patterning and supporting cell differentiation are also partially disrupted. Diffusible factors involved in patterning are reduced (Fgf8) and factors involved in cell-cell interactions are affected (Jag1, Hes5). Despite the presence of many HCs with stereocilia these mice are deaf, possibly owing to HC and OC patterning defects. This study provides a novel approach to disrupt OC development through modulating the HC-specific intracellular TF network. The resulting disorganized OC indicates that normally differentiated HCs act as 'self-organizers' for OC development and that Atoh1 plays a crucial role to initiate HC stereocilia differentiation independently of HC viability.
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Affiliation(s)
- Israt Jahan
- Department of Biology, College of Liberal Arts & Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Ning Pan
- Department of Biology, College of Liberal Arts & Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Jennifer Kersigo
- Department of Biology, College of Liberal Arts & Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Bernd Fritzsch
- Department of Biology, College of Liberal Arts & Sciences, University of Iowa, Iowa City, IA 52242, USA
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17
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Abstract
Cochlear hair cell bundles, made up of 10s to 100s of individual stereocilia, are essential for hearing, and even relatively minor structural changes, due to mutations or injuries, can result in total deafness. Consistent with its specialized role, the staircase geometry (SCG) of hair cell bundles presents one of the most striking, intricate, and precise organizations of actin-based cellular shapes. Composed of rows of actin-filled stereocilia with increasing lengths, the hair cell’s staircase-shaped bundle is formed from a progenitor field of smaller, thinner, and uniformly spaced microvilli with relatively invariant lengths. While recent genetic studies have provided a significant increase in information on the multitude of stereocilia protein components, there is currently no model that integrates the basic physical forces and biochemical processes necessary to explain the emergence of the SCG. We propose such a model derived from the biophysical and biochemical characteristics of actin-based protrusions. We demonstrate that polarization of the cell’s apical surface, due to the lateral polarization of the entire epithelial layer, plays a key role in promoting SCG formation. Furthermore, our model explains many distinct features of the manifestations of SCG in different species and in the presence of various deafness-associated mutations.
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